1. Field of the Invention
The invention relates to a flapper valve having particular utility when employed as a flow control valve in a tubing string for subterranean wells.
2. Description of the Prior Art
Many types of valves have heretofore been proposed for installation in the tubing strings of subterranean wells for interrupting the flow of fluid therethrough. Included in such prior art devices have been flapper valves which are pivotally mounted about a horizontal axis for movement into a blocking position across the vertical bore of the tubing string. Such valves have, however, required either a restriction in the flow path defined by the tubing string or an excessive external enlargement relative to the tubing string to accommodate the pivotal mounting of the flapper valve. Flapper type valves are desirable adjuncts for controlling the flow of fluids in a subterranean well since they are reliable and easily operated, but heretofore, their space requirements have been excessive.